Meat tenderizing machine



June 22, 1943- L. A. LARSON ETAL MEAT TENDERIZING MACHINE 2 Sheet-Sheet1 fade/26075. 3160M] waif ZdiCfiUiL *W div/76?]? Leo #519422? Filed June1 9, 1940 June 22,1943. I LARSON HAL 2,322,243

MEAT TENDERIZING MACHINE Filed June 19, 1940 2 Sheets-Sheet 2PEI/67226071- Z lleaiuz fllarjam Leo ar W*W Patented June 22, I943 MEATTENDERIZING MACHINE Leonard A. Larson, Chicago, Ill., and Leo W. Hart,Milwaukee, Wis., asslgnors to Kwik Steak Machine Co. of America,Milwaukee, Wis'., a

- corporation of Wisconsin Application June 19, 1940, Serial No. 341,254

11 Claims.

This invention relates to improvements in meat tenderizing machines andmore particularly to such-machines for breaking down the fiber structureof meat by subjecting it to a multiple-incision cutting action.

.The principal difierence between prime quality steak cuts of meat andthe other far more abundant and proportionally less desired and cheapercuts as well as lower grades of meat resides, of course, in the tougherfiber structure.

From a nutritional standpoint, however, there is little if anydifference-between the various cuts or grades of meat. By breaking downthe fiber structure or tenderizing the meat as by a more or less uniformand repeated cutting action to sever the fibers intounobjectionableshort lengths the cheaper cuts and grades of meat can be renderedpractically as desirable from an epicurean standpoint as the moreexpensive cuts.

It has heretofore been proposed to tenderize by subjecting the morefibrous meat to the cutting action of manually actuated multi-knifecutters. The prior machines for this purpose have been slow andoftentimes cumbersome and laborious to operate. Some have not been assanitary as desirable, or have been of such complicated or inconvenientmechanism as to encourage neglect of proper cleaning. Generally also,the prior machines and methods have been limited to the treatment ofwhole steaks only.

A general object of the present invention is to provide an improved meattenderizing machine in which the cutting means is power driven forrelatively high speed operation.

Another object is to provide a machine of this character having noveldriving means.

Still another object of the invention is to provide such a machine inwhich the cutter head mechanism embodies improved means forautomatically returning the cutter head to an elevated position after acutting operation.

A further object of the invention is to provide a novel method of andmeans for uniting and tenderizing discrete pieces and particles of meatinto full steaks.

A still further object of the invention is to provide in a machine ofthe foregoing general character means for applying flattening pressureto the meat undergoing treatment.

Yet another object of the invention is tojprovide a readily adjustablecutter head and pressure applying means.

Additional objects of the invention are to provide an improved cutterhead assembly, and an improved quick detachable connection between thecutter head andits plunger.

Other objects and advantages will become apparent in the followingdescription and from the accompanying drawings in which:

Figure l is a fragmental side elevational view of a tenderizing machineembodying the features of the invention and with parts broken away andin section for clarity of illustration.

Fig. 2 is a transverse vertical sectional view through one side of thecutter head taken substantially along line 22 of Fig. 1.

Fig. 3 is a front elevational view of the machine.

Fig. 4 is a horizontal sectional view taken substantially along line 4-4of Fig. 3 and showing the top of the cutter head.

Fig. 5 is a horizontal sectional view through the cutter head assemblytaken substantially along line 5-5 of Fig. 3.

Fig. 6 is a fragmentary horizontal sectional detail view through thecutter head plunger and its guideway, taken substantially in the planeof line 6--6 of Fig. 1.

While the invention is susceptible of various modifications andalternative constructions, we have shown in the drawings and will hereindescribe in detail a preferred embodiment, but it is to be understoodthat we do not thereby intend to limit the invention to the specificform disclosed but intend to cover all modifications and alternativeconstructions falling within the spirit and scope of the invention asexpressed in the appended claims.

A tenderizing machine according to the pres- I ent invention is adaptedto be power driven at relatively high speed. It has a reciprocatingcutter assembly or head including a pressure and stripper plate soarranged that throughout the time the tenderizing knives penetrate themeat in each cutting stroke, the meat is pressed down uponthe meatboard. On each return stroke the pressure and stripper plate rises fromthe surface of the meat and permits rotation of the head so that on thenext cutting stroke the knives will penetrate the meat at a differentangle. As the cutting under pressure proceeds, pieces of meat of varyingthickness become uniformly flattened steaks, the thickness of which isdetermined by adjustments for limiting the pressure approach of thecombined pressure and I stripper plate. This cutting and pressingtreatment is effective not only for beef but is also singularlysuccessful with veal which ordinarily is difficult to tenderize becauseof the resilient or. rubbery character of veal fibers. In fact, it hasbeen found that by this treatment small irregular pieces of meat,whether beef or veal, are successfully tenderized and united into whatto all intents and purposes appears and may be handled like a tenderizedone-piece steak. Moreover, coarse ground meat subjected to the pressureand tenderizing treatment similarly agglomerates to form a. completesteak hardly discernible from a tenderized whole piece of meat. Theagglomerate steak is of unusually 1 within a forwardly overhangingportion of a su porting frame l2. The plunger II is adapted to, bereciprocably actuated by power driving means generally designated I 3.In the present instance the driving means I3 is of rotary type and isarranged to be driven by a suitable prime mover such as an electricmotor |4 acting through the medium of a speed reducing transmissionwhich is assembled within a casing l5.

In the form illustrated, the machine may comprise two separable units,the frame l2 together with the cutter head I and the driving means l3constituting one unit which for convenience may be designated theftenderizer unit, and the motor l4 and speed reducer assembly l5 formingthe other unit which may be termed the power unit." Through thisarrangement the driving and power units may be detached and the powerunit used for driving other devices such as a meat chopper or grinder(not shown). A bracket l5 which projects forwardly from the transmissioncasing l5 for supporting the grinder is utilized also for assisting incooperatively supporting the tenderizer unit and for this purposeprojects into engagement within the supporting frame l2 which for thispurpose may be formed as a hollow casting. Both units may convenientlybe mounted in proper operative relation upon a base plate II. The baseplate I! may project forwardly to underlie the cutter head In and toprovide a convenient support for a slidable meat board l8 upon which isplaced meat l8 to be treated. The meat board |8 may be of any desiredlength and adapted to carry a substantial number of steaks.

The cutter head I0 carries a series of elongated knife blades 28. Eachblade is slotted inwardly from its cutting edge to form a series ofequally spaced narrow bladelets 2|. All of the blades are securedtogether by means of tie rods 22 with the cutting edges of the bladelets2| arranged in a uniform plane. The tie rods 22 extend through the backmargins of the blades and through spacer blocks 23 (Fig. 2) by which theblades are maintained in equally spaced parallel relation. The knifeassembly is detachably secured to the face of a rectangular head plate24 by means of clamping and attachment bars 25 which are secured inplace at the opposite sides of the knife blade assembly on the outerends of the tie rods 22 and are forced inwardly into clamping relationby means of nuts 21. Each of the attachment bars 25 has a portionprojecting beyond the back edge plane of the knife blades 20 and isformed with an inwardly facing longitudinal groove 28 to receive therespective side edge of the head plate 24 removably. Through thisarrangement the knife assembly is adapted to make a plurality ofparallel series of uniform, short incisidns into the meat being treated.Should any blade become damaged or require sharpening, it can easily bereleased from the assembly by unscrewing the nuts 21 and removing thetie rods 22. A handle 29 may be mounted to project forwardly from thehead plate 24 for convenience in manipulating the cutter head.

In order to place the meat under pressure while it is being cut by theknife blades, means. is pro vided such as a rectangular pressure plate30 which forms a part of the tenderizing head in (Figs. 1, 3 and 5).This pressure plate 30 is formed with a plurality of spaced parallelslots 3| Just wide enough for passage therethrough of the knife blades20 and is supported in spaced parallel alinement with the head plate 24by means of a plurality of guide rod 32, herein shown as four in numberlocated one adjacent to each comer of the plates. The guide rods arefixedly secured to the pressure plate 30 and extend slidably throughportions of the head plate 24 which extend beyond the opposite ends ofthe knife blades 20. Resilient means such as helical compression springs33 encircling the guide rods 32 act between the plates to normallymaintain a maximum adjusted separation therebetween. Wing nuts 34threaded onto the ends of the guide rods 32 projecting above the headplate 24 serve to draw up the guide rods against the compression of thesprings 33 to define the adjusted spacing between the head and pressureplates. By preference this spacing is such that in the inactive ornon-cutting condition of the tenderizer head Hi the cutting tips oredges of the'bladelets 2| are protectively drawn up into the slots 3|.

.As a result of the resilience afforded by the springs 33, the pressureplate 30 may yield when in the cutting stroke of the tenderizing head Inthe plate bears upon and is held against full downward movement by themeat being treated. This allows the bladelets 2| toproject through thepressure plate into the meat as shown in dotdash outline in Figs. 1 and3. Upon release of the tenderizing head In for return to the initial orinactive position, the springs 33 cause the pressure plate 30 toautomatically assume its adjusted or extended position relative to thehead plate '24 so that the bladelets 2| are retracted and stripped cleanof any adhering particles of meat. while the meat is still under atleast some pressure.

Means such as a pair of stop screws 35 may be provided for limiting theapproach of the pressure plate 30 to the meat board l8 whereby todetermine the extent of flattening of the meat by the pressure plate.These stop screws are threaded through the pressure plate 30, preferablyadjacent to the front and rear ends thereof, and are arranged to engagethe meat board |8 when the pressure plate has reached the preferredspaced relation to the board. In this manner a uniform thickness can bepredetermined for the treated steaks. The stop screws may be held inadjusted condition by means of lock nuts 31.

A detachable connection between the tenderizing head Ill and thecarrying stem or plunger H is provided by resiliently retractibleplungers or pins 38 (Figs. 3 and 4) carried by the head plate 24 andextending endwise into a peripheral connecting groove39 at the lower endof the plunger.

In' the present instance the connecting pins 38 are two in numberconveniently located in coaxial alinement at opposite sides of the headl0 and are slidably mounted in upstanding bosses 40 rising fixedly fromthe upper face of the head plate 24. necting pins 38 extend through anupstanding central annular flange or hollow boss 4| on the head plate 24which provides a sliding socket 42 The inner end portions of the conmentwithin the connecting groove 39. At their outer ends the connecting pinsmay be equipped with knurled heads 45 to facilitate manual retraction-ofthe pins for releasing the tenderizing head I when it is desired toremove the same as for cleaning. Thus, the tenderizing head may veryconveniently be kept in a thoroughly sanitary condition. The pin andgroove connection, moreover, permits the tenderizing head to rotatefreely about the plunger ll.

Means is provided for normally urging the plunger ll upwardly to supportthe tenderizing head It) in spaced relation to the meat board l8, thatis, in the inactive ornon-cutting position. Herein such means comprisesa helical compression spring 41 (Figs. 1 and 6) which is housed within asuitably dimensioned axial bore 48 in the plunger and arranged to exerta continuous substantially axial upthrust upon the plunger. The bore 48preferably extends inwardly from the lower end of the plunger II and isclosed at the upper end by a cross head 49 against which the upper endof the spring 41 bears. At its lower end the spring rests upon astationary transverse pin or abutment 50 which has its ends fixedlysecured in the adjacent portion of the frame l2 at opposite sides of theplunger and extends through diametrically alined longitudinal slots 5|therein. The slots 5| are of such length that they permit a full rangeof recipro- 55 is releasably secured within a forwardly projectinghollow boss 69 by means such as a winghead set screw 10. Thisarrangement permits convenient removal of the sleeve bearing when thetenderizing unit is detached from the power unit to permit other uses ofthe latter.

From time to time it may become necessary to adjust the length of theplunger II for varying the approach of the cutter blades to the meatboard l8. For this purpose, the plunger may be formed in two sections,the upper section being in the form of a readily accessible cal movementfor the cutting strokes of the plunger ll. As a result of thisarrangement, when the plunger II is driven downwardly in a cuttingstroke by a counterthrust in opposition to the spring 41, the latter isplaced under compression. Upon release of the counterthrust, thecompressed spring 41 automatically returns the plunger and tenderizinghead to the inactive or non-cutting position. It may also be noted thatthe pin 50 holds the plunger ll against rotation Smooth, uniformtranslation of the rotary motion of the driving means l3 into thereciprocal motion of the plunger II is effected in the present instanceby means such as a circular disk cam 52 which rides against antifrictionmeans such as a roller 53 mounted at the upper end of the plunger H. Thecam 52 is mounted eccentrically upon a shaft 54 and in its rotationintermittently thrusts the plunger ll axially down in opposition to thecompression spring 41 to drive the tenderizing head into cuttingposition. This driving arrangement is without dwells in motion, issilent and entirely free of jarring vibrations.

The shaft 54 extends in a front to rear direction over the plunger IIand is journaled at the front of the supporting frame l2 in a shortbearing 55 and at the rear in a longer bearing 56. A retainer disk 51 issecured to the forward extremity of the shaft 54 by means of a bolt 58,

forked head (I which has a stem 12 threaded into the cross head 49 andarranged to be locked in any adjusted position by means ofa lock nut 13.Thus, to increase or decrease the overall length of the plunger II thelock nut 13 is loosened and the head ll turned to-the desired relativeposition. The adjusted condition is then maintained by resecuring thelock nut 13.

As a protective measure, moving parts of the driving mechanism such asthe cam 52 and the pinions 59 and 60, may be enclosed by. removablecasings or hoods 14 and 15, respectively. These hoods are preferablyconstructed to be slid on or off.

In the operation of the machine, the meat H) to be treated is placedupon the meat board l8 under the tenderizing head Ill and the motor I4is started to actuate the driving means 13. Thereupon, the driving cam52 is rotated at high speed in an eccentric path which alternatelycauses the plunger II and tenderizing head In to be forced downwardly ina cutting stroke and then released for return by the spring 4'! tonon-cutting position, the transition from thrust fore the plate 30isreleased from the meat and returned to the inactive position. Betweeneach cutting stroke the tenderizing head l0 may be rotatably shiftedabout its axis by means of the handle 29 so that at the next stroke thebladelets will cut into the meat at a different angle,

and a pinion 59 is secured to the rear end of the shaft. Meshing withthe pinion 59 is a driving gear 80 carried by a stub shaft 6| which isjournaled in a bearing sleeve 62 within the adjacent part of the framemember l2. A retaining disk 63 is secured to the forward end of the stubshaft 6| by means of a bolt 64. The rear 'or outer end portion of thestub shaft Bl extends beyond the driving gear through a sleeve bearing65 and has a squared ofi end portion 61 which fits into a transmissionsocket member 68 within the transmission housing l5. The sleeve bearingSuch shifting may, in the present compact embodiment of the invention,be effected through any preferred range within an arc of roughly 240 asindicated generally by the dot-dash outline positions in Fig. 4, theonly limitation upon full rotation being the rear or standard portion ofthe frame l2 which is in the way of the projecting handle 29. Inpractice it has been found that good results are obtained where thecutting strokes of the tenderizing head H! are at the rate of up to 220per minute and the head is swung gradually in an arc of about in thetreatment of each steak. As a result, the meat may quickly be subjectedto a great many cuts at a large irom the machine for cleaning purposes,and the arrangement of the head is such that it can easily be dismantledfor repair or sharpening of the blades. By placing the meat underpressure simultaneously with cutting, not only is the tenderizing ofwhole pieces of meat facilitated but it is also possible to tenderizeand unite separate pieces or particles of meat into a substan- 1. Amachine of the character described com-.

prising, in combination, a framework, a vertically reciprocable hollowplunger carried by said framework, a meat-cutting head at the lower endof said plunger, means for reciprocably driving said plunger, meanstending to urge said plunger upwardly when it is in the lowermostposition of its reciprbcal cycle including a compression spring elementwithin the plunger, and abutment means held immovable relative to saidplunger engaged by the lower end of said spring element.

2. A machine of the character described comprising, in combinatiom'aframework, a vertically reciprocable hollow plunger carried by saidframework, a meat-cutting head carried by the lower end of said plunger,means for reciprocably driving said plunger, a compression spring withinsaid plunger, said plunger having diametrically opposite longitudinalslots therein adjacent to the lower end of said spring, and a transversepin fixedly supported by said framework extending 3. In combination in ameat tenderizing ma chine of the character described, a supporting framehaving a forwardly projecting overhanging portion, a verticallyreciprocable plunger carried by said overhanging portion and having arelatively rotatable tenderizing head at its lower end, said plungerhaving an axial bore therein and diametrically alined longitudinal slotsat opposite sides of said bore, compression spring means within saidbore, a pin extending through said slots and fixedly anchored in saidoverhanging portion to hold said plunger against rotation and providingan abutment for one end of said spring means, the opposite end of saidspring means bearing against said plunger, antifriction means carried bythe upper end of said plunger, and a rotary cam cooperating with saidantifriction means to actuate said plunger against the compression ofsaid spring means for moving said head into tenderizing position.

4. In combination in apparatus of the character described, a supportingframe, a vertically reciprocable hollow plunger carried by said upperend of said plunger and extending axially through the upper end ofsaid'spring.

5. In combination in a. meat tenderizing machine of the characterdescribed, a vertically reciprocable plunger, a tenderizing head carriedby the lower end of said plunger for acting on meat supportedtherebelow, means providing a fixed abutment adjacent the lower portionof said plunger, a compression spring bearing at its lower end againstsaid abutment and bearingat its upper end against an upper end portionof said plunger to place the plunger under continuous upthrust fornormally holding said head in the inactive position, and counter-thrustmeans for driving said head into tenderizing position in opposition tosaid upthrust means.

6. A meat tenderizing machine comprising, in combination, a verticallyreciprocating member, a head plate supported by the lower end of saidreciprocating member, a knife blade assembly including a plurality ofbladelets' and spacers secured together by means of tie bolts to form aself-contained unit, and means on said unit'for detachably securing thesame to said head plate comprising attachment bars engageable with theedges of said head plate and arranged to be clamped against such edgesby said tie bolts.

'7. A meat tenderizing machine according to claim 5 wherein thecounter-thrust means comprises a circular cam eccentrically mounted upona rotatable drive shaft and operatively disposed edgewise over the upperend of the plunger.

8. A meat tenderizing machine according to claim 5 in which the plungerincludes means adjacent to the counter-thrust means for adjusting theextent to which the tenderizing head is driven into the tenderizingposition.

9. A meat tenderizing machine according to claim 5 wherein a stationaryframe supports the plunger and fixed abutment and has spaced bearingmeans located above and at respective opposite sides'of the plunger, andthe counter-thrust means comprises a driven shaft journaled in saidbearing means and overlying said plunger with the axis of the shaft andthe axis of the plunger perpendicularly intersecting, aplunger-reciprocating cam being fixed upon said shaft and hearingdownwardly edgewise upon the upper end of the plunger.

10. A meat tenderizing machine according to claim 5wherein a drivenshaft is journaled on a horizontal axis intersecting the axis of theplunger above the upper end of the plunger and has aplunger-reciprocating cam member fixed thereon as a unit to provide thecounter-thrust means referred to, the upper end of the plunger having aforked head, and an anti-friction roller supported by the forked headand rotatably engaging the cam member.

11. A meat tenderizing machine as set forth in claim 5 wherein thecounter-thrust means includes a driven cam, and the upper end of theplunger has a head carrying an anti-friction roller cooperating with thecam, said head being longitudinally adjustable relative to the remainderof the plunger so as to decrease or increase the length of the plungerand thus control they approach of the tenderizing head to a meat supportin the tenderizing position of the head.

LEONARD A. LARSON. LEO W. HART.

